Gradebook calculation changes

Note: The following information only applies if you see a message displayed in the gradebook following a site upgrade, or after restoring a course backup from a different version of Moodle.

Occasionally there are error fixes which can affect gradebook calculations in certain courses. As part of the upgrade process, such courses are identified and a message is displayed in the gradebook informing teachers that error fixes may result in some grades being changed. Details of these changes are provided below. The 8-digit version number is the date of the fix.

It is recommended that the errors are fixed by clicking the button 'Accept grade changes and fix calculation errors'. Until this is done, the message will continue to be displayed in the gradebook (only for teachers; students can't see it). The old gradebook calculations will still be used (ensuring grades remain unchanged), however they are likely to result in more errors if grades are updated in the future.

20150619 - Calculation of extra credit item weights when using natural aggregation

Two errors were fixed:

1. Overriding the weight of the extra credit item can lead to changes in other items' weights and random final grades
2. The automatic weight of an extra credit item was dependent on the overrides of the normal item's weights

The second error was especially noticeable for students with excluded grade items (for example, when they are hidden or empty).

For example, a category has two normal grade items and one extra credit item. If the maximum grades for each item are the same, the weights of the three items will be: 50%, 50% and 50%. However if the weights of the normal items are overridden to be 50% and 50%, then the weight of the extra credit item would become 0%. If the teacher overrode the weight of the first item to 80%, the second item would automatically become 20% (correct) and the extra credit would also become 20% (incorrect).

The correct behaviour (after the fix): If the weight of extra credit item is not overridden, it should be itemmaxgrade / totalmaxgrade , where totalmaxgrade does not include the extra credit item. In the example, the weight of the extra credit item should always be 50%.

See MDL-49257 for further details including screenshots.

20150627 - Calculated grade items

Three errors were fixed:

1. Changing the maxgrade of a category item with a calculation using "Natural aggregation" is now possible.
2. A change to the minimum or maximum grade value will immediately be displayed without the need for regrading to be triggered regardless of what the setting "Min and max grades used in calculation" is set to.
3. With the setting "Min and max grades used in calculation" set to "initial min and max grades" calculated grade items are correctly displayed out of the max and min grade for that item.

The first two errors should have no impact on existing grades in the gradebook. The last error fix does have the potential to change existing grades. If you have the setting of "Min and max grades used in calculation" set to "initial min and max grades", calculated grade items with a maximum and minimum grade value that is not 100 and 0 respectively will have it changed to match the current minimum and maximum.

See MDL-48239 for further details.